1. Field of the Invention
The present invention relates to a network for providing MPLS-VPN (MultiProtocol Label Switching-Virtual Private Network) services and more particularly to a method and a device for identifying the interface of a virtual router.
2. Description of the Background Art
Today, a VPN virtually implementing, e.g., a company network on an IP (Internet Protocol) network is attracting increasing attention. Particularly, a MPLS-VPN using MPLS easily provides a VPN solution for supporting private addresses while securing customer data.
However, a conventional MPLS-VPN system has a problem that an OSPF (Open Shortest Path First), an RIP (Routing Information Protocol) and other existing routing protocols cannot operate between VPN user sites via virtual routers. Another problem is that label merging and penultimate hop popping are not practicable within an MPLS network.
Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 10-56481, 11-191776, 11-266278 and 2000-138711.